What are the precautions for using the tester?

　　2. Measurement cannot be performed after rain, when the soil absorbs too much water, or when the climate, temperature, pressure, etc. change dramatically.

　　3. There should be no stray current or polarized soil near the measured ground pole.

　　4. The detection needle should be kept away from large metal objects such as underground water pipes, cables, and railways. The current pole should be kept at least 10m away, and the voltage pole should be kept at least 50m away. If the above-mentioned metal objects are not connected to the grounding grid, the distance can be shortened by 1/2~1/3.

　　5. Pay attention to the position where the current electrode is inserted into the soil, and the grounding rod should be at zero potential.

　　6. The connecting wires should use well-insulated wires to avoid leakage.

　　7. There must be no electrolytes or rotting corpses at the test site to avoid illusions.

　　8. The test should be carried out when the soil resistivity is high, such as in early winter or in the dry season of summer.

　　9. Check the accuracy of the instrument at any time (send it to the measurement unit for inspection and certification once a year)

　　10. When the sensitivity of the galvanometer is too high, the voltage pole of the potential probe can be inserted shallower into the soil. When the sensitivity of the galvanometer is not enough, water can be injected along the probe to make it moist.